For the interchangeable plugs available in the current market, general interchangeable plugs are not provided with light and hence one cannot find the corresponding jack under the dark. Even for the interchangeable plugs with LED lamp as disclosed in prior art, they apply the plugging-in and out mode of connection, and render inconvenience in usage. For the other general interchangeable plugs, their forms are susceptible to the surrounding and therefore pose a problem in security level.